Predicting correction factors for differences in initial weight among genetic groups of common carp in communal testing

Testing different genetic groups of common carp by stocking them together into ‘communal ponds’, requires correcting observed weight gains for differences in initial weight among the tested groups. Reliable estimation of correction factors, by the multiple nursing technique, requires a minimum difference of 15 g in initial weight between multiply nursed samples. Empirical estimates of correction factors are biassed by errors in estimating initial weight differences. No consistent differences were isolated in the correction factors generated from different genetic groups.A multiple regression analysis based on data from ten tests generated the following prediction equation: b=4.543−0.113 X.+0.00671 Y. (R=0.716) where b=predicted correction factor; X.=mean initial weight; Y.=mean weight gain. Predicted correction factors, generated from the analysis of a large set of data, are at least as reliable as empirical estimates from a single experiment. Their use enables an economy in facilities, which would otherwise be required for producing and testing multiply nursed samples. The application of this technique to other fish species is discussed.     

Genetic variation in seine escapability of the common carp

During the years 1970, 1971 and 1972, 26 genetically diverse groups of common carp were tested in communal ponds, i.e., all the tested groups were co-stocked into the same ponds. These groups included inbred and crossbred domesticated European carp, one representative of the Chinese Big-Belly race, and several hybrids between the two races. The results led to the following conclusions concerning the genetics of seine escapability. (1) The Chinese race is much more adept at escaping seines than the European race. (2) The hybrids between the two races are intermediate with incomplete dominance of the higher escapability of the Chinese race. (3) Genetic variation was found within the European race with a strong dominance, or heterosis, of higher escapability. (4) Body weight as well as growth capacity were not associated with seine escapability. The absence of correlation between growth capacity and seine escapability contradicts earlier results that suggested a strong genetic correlation between the two characters.     

转生长激素基因鲤鱼的生长研究

本报导了生长激素基因对鲤鱼生长的影响。经池塘对照实验表明，转生长激素基因鲤鱼的快速生长效应比正常鲤鱼明显，而且由转生长激素基因阳性性成熟鲤鱼经人工催产繁殖的子一代群体中，仍表现出快速生长的特性。这一结果，为能获得一个转外源生长激素基因并具快速生长特性的遗传稳定的转基固鲤鱼核心群体提供了可靠的数据。     

Communal testing,a method of testing the growth of different genetic groups of common carp in earthen ponds

Communal testing consists of stocking the different genetic groups to be tested into the same (communal) pond. In this system, genetic differences between groups of fish and differences in pond productivity are not confounded, as they are in separate testing. Communal testing reduces the number of replications required and enables larger numbers of groups to be tested in a smaller number of ponds. Growth testing in communal ponds means that the testing environment and the commercial production environment in which the results of genetic investigations are to be applied are not identical. This difference is due to the mutual competitive interactions between test groups in communal ponds, which cannot occur when they are stocked separately. Interactions may be due to differences in initial weight between the groups, or to differences in competitive ability not associated with differences in initial weight. The methodological investigations which allow these sources of bias to be removed are described. The effect of differences in initial weight is corrected with the aid of the environmentally generated coefficient of regression of weight gain on initial weight in a communal pond. This regression requires empirical estimation in each test, by the multiple nursing technique, specifically constructed for this purpose. Relative growth rankings of paris of test progenies were identical when each group was stocked separately into a series of replicated ponds and when both were stocked together into communal ponds. Thus growth estimates from communal testing are reliable predictors of expected genetic differences in separate ponds.Communal testing allows any pond or other growth vessel to be used as a testing facility, irrespective of its area or aquacultural management. Alternatively, it enables breeding studies to be integrated with other unrelated investigations. This results in a more rational utilization of facilities and the possibility of isolating and estimating interactions between experimental variables.     

松浦镜鲤[(散鳞镜鲤×德国镜鲤)F_1]主要经济性状及遗传特性

从1986至1990年,在黑龙江水产研究所松浦试验场,用本所培育的散鳞镜鲤与由联邦德国引进的德国镜鲤进行了品系间杂交,获得了一个形态与两亲本稍有不同,而生长等经济性状具有明显超亲优势的杂交种——松浦镜鲤。根据对体长、体高、头长、吻长、眼径、尾柄长和鳃耙数等16个可数、可量性状的测定。松浦镜鲤在头长、吻长、眼径、尾柄长和鳃耙数等5个性状上与双亲不同,而其它性状都界于双亲之间,体高、体厚偏向母本,而尾柄高、鳃耙数偏向父本。因此表现出头小、吻延长,眼径扩大,鳃耙数增加等有利运动和摄食,根据4年的池塘生长对照和抗寒、抗病测验,松浦镜鲤一至三龄鱼的越冬成活率分别比双亲高70.3％、116.2％和17.8％。池塘饲养成活率一至三龄鱼分别比双亲高10％、18.5％和14.7％。由于池塘成活率高,因此,群体产量一至三龄鱼分别比双亲高81.3％、63.6％和59.9％(三个池塘的平均值)。个体体重瞬时增长率一至三龄鱼分别比双亲快7.7％、6.5％和25.82％(三个池塘的均值)。含肉率比双亲均值高8.9％。     

Effects of feeding rates on growth and production of Nile tilapia, common carp and silver carp polycultured in fertilized ponds

Abstract In an attempt to identify appropriate feeding rates for multispecies of fish raised in fertilized earthen ponds, the present work was conducted over a 19‐week experimental period to establish the growth performance, production and body composition of Nile tilapia, common carp and silver carp fed 0.0%, 0.5%, 1.0%, 3.0%, 5.0% biomass and to apparent satiation (treatments). Twelve ponds were stocked with a similar number and weight of each fish species. Two ponds were assigned to each of the treatments, and a 25% protein pelleted fish feed was used to feed fish at the specified rate of feeding. At the end of the experiment, growth, weight gain, survival, yield and body composition of fish groups were affected by the treatments. The economic effectiveness also varied among treatments. The most conspicuous attribute of the feeding rates was its lack of influence on growth (g day^?1), weight gain (g per fish), yield (kg ha^?1) or body composition of silver carp. The results of whole‐body proximate analysis indicated that various feeding rates had either an irregular pattern or no effects on the protein and ash gain per 100 g of fish body weight (bw) gain. The most notable exceptions were significant (P < 0.05) increases in body fat and gross energy gains in Nile tilapia, common carp and silver carp accompanied by decreases in percentages of moisture (but not in silver carp) as feeding rate increased. Among the six different feeding levels, feeding to apparent satiation (feed amount was equivalent to 2.67% of fish bw day^?1) appeared to be optimal, as it significantly (P < 0.05) supported the highest fish production, income and net profit compared with all other treatments except for the 3% feeding level, for which the differences in those measurements were comparable.     

Growth testing of two breeds of common carp, Cyprinus carpio L. (Hungarian mirror and Třeboň scaly carp), in ponds with low and high stocking density

The growth of two breeds of common carp, Cyprinus carpio L., was tested in ponds under the climatic conditions of South Bohemia. T?eboň scaly carp (TR) and Hungarian mirror carp (M2) were kept in both low and high stocking densities during the second growing season and then stocked together for communal testing during the third growing season. Before the communal testing, the mean initial weights of fish from low‐ and high‐density stocks differed significantly (374.1 vs. 227.7 g for the TR breed and 766.7 vs. 317.3 g for the M2 breed respectively, P<0.01). After communal testing, mean weights of fish from low‐ and high‐density stocks gained 761.8 vs. 543.8 g for the TR breed and 1339.7 vs. 706.7 g for the M2 breed respectively. These observed weights were also significantly different (P<0.01). However, the test of corrected weight gain, i.e. gain not related to the initial weight of fish, revealed insignificant differences (P>0.01) between the weight gains after correction, i.e. the effect of different initial weights was successfully eliminated. These results seem to confirm the applicability of this method for the assessment of growth of purebred common carp under the climatic conditions of Central European fish farms.     

Growth, Yield, Dressout, and Net Returns of Bighead Carp Hypophthalmichthys nobilis Stocked at Three Densities in Catfish Ictalurus punctatus Ponds

Abstract— Alternative fish species that can be cultured together with catfish Ictalurus punctatus provide an opportunity to diversify caffish farms. A 2-yr study was conducted in 0.10-ha earthen ponds to evaluate the effect of bighead carp (BHC) stocking density on growth, yield, dressout yield, and net returns. Initially, bighead carp (average weight of 22 g) were stocked at rates of 380, 750, or 1,130 fishha in ponds with catfish. Caffish were cultured under commercial conditions by stocking caffish at a density of 12,500/ha, aerating nightly and feeding at an average rate of 82 kgha per d. Stocking rates for 2-yr-old fish were reduced to 77, 260, and 435/ha in the second growing season. There were no significant differences among treatments ( P > 0.05) in summer growth of bighead carp in either year. Bighead carp stocked at 1,130 fishha had significantly higher yields than those stocked at 380/ha, but did not reach minimum market size of 2.2 kg during the first year ( P > 0.05). There were no significant differences ( P > 0.05) in caffish growth, yield, survival, or feed conversion ratios due to the bighead carp stocking densities. Partial budget analysis indicated that net benefits were positive for all three treatments over a range of prevailing prices of bighead carp. Bighead carp production in catfish ponds is economically feasible over a wide range of prices. Given the market risk of producing smaller fish at the higher density, the medium density is the preferred stocking density of fingerling bighead carp in catfish ponds.     

Appropriate Timing of Supplemental Feeding for Production of Nile Tilapia, Silver Carp, and Common Carp in Fertilized Polyculture Ponds

In an attempt to identify appropriate times for initial application of supplemental feed in polyculture fertilized fish production earthen ponds, a study was conducted for 19 wk to establish the growth performance, yield, survival, and body composition of Nile tilapia, common carp, and silver carp as influenced by four different feeding regimens (treatments). The four treatments were: 1) supplemental feeding beginning at onset of the experiment (T-I) (control treatment); 2) 6-wk delay of feeding after fish stocking (T-II); 3) 13-wk delay of feeding after fish stocking (T-III), and 4) no supplemental feed application (T-IV). Two ponds were assigned to each treatment and each pond was stocked with a similar number and weight of each fish species. A commercial pelleted fish feed (25% protein) was used to feed fish in T-I, T-II, and T-III at 3% of their body weight, twice a day. At the end of the experiment, fish species (except for silver carp) in T-II showed weight gain, growth rates, and yields significantly higher than fish in T-III or T-IV. Also, the total fish production and net profit in T-II were significantly higher than in T-III or T-IV. Fish species in T-II showed weight gain, growth rates, survival rates, and yields similar to those of T-I (control treatment) with no significant differences. The amount of feed consumed by fish in T-II was reduced by approximately 7.3% compared to that consumed by fish at T-I. Moreover, there was increase in th net profit in T-II by 4.8% over that achieved in T-I. Therefore, T-II appears to be the most appropriate among the tested feeding treatments and recommended for use in order to achieve the best growth, production, and net profit.     

Effects of Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae) infection on growth performance and mortality in carp, Cyprinus carpio L.

Abstract. Outbreaks of sanguinicoliasis have been reported from several carp, Cyprinus carpio L., farms in Britain since 1978. The parasitic agent, Sanguinicola inermis Plehn, 1905, affects young of the year carp in nursery ponds. In the outbreak studied mortality as high as 90% occurred within the first 2–3 months of life. The prevalence of infection in surviving fish was 74% and their growth performance was measured over a period of 16 weeks under optimum aquarium conditions. The fish showed a poor growth performance with depressed specific growth rates and daily live weight gain. Food utilization, food conversion rates and protein efficiency ratios were inferior in both lightly and heavily infected groups of fish. A further 30% mortality occurred in the heavily infected group during the experiment, 14 months after the initial infection, indicating serious long-term effects of the parasite. There appears to be little value in retaining infected fish and complete destruction of affected stocks and disinfection of the farm is recommended where possible.     

三角帆蚌对综合养殖水体水质及鱼蚌生长的影响

在草鱼(Ctenopharyngodon idellus)养殖池中进行鱼蚌综合养殖试验,以探究三角帆蚌(Hyriopsis cumingii)吊养密度和深度对水质、鱼和蚌生长的影响。试验共分4个处理组,三角帆蚌放养模式分别为对照组0只/m^3(C)、水下40 cm处单层吊养9只/m^ 3(D-6)、水下40 cm处单层吊养18只/m^3(D-12)、水下40 cm和80 cm处双层吊养18只/m^ 3(S-12)。结果显示:试验期间,各组透明度和溶氧均随时间的延长呈现下降趋势。吊养组(D-6、D-12、S-12)TN、NH+4-N和COD的平均含量均低于C组。各组TP平均含量无显著差异。吊养三角帆蚌后草鱼的成活率和增重率显著提高,其中D-12组鱼和蚌的存活率和增重率最高。同等三角帆蚌密度下,单层吊养(D-12)的水质化学指标、鱼和蚌的存活率和增重率均优于双层吊养(S-12)。从改善水质、鱼蚌生长情况等指标考虑,在草鱼养殖池中,三角帆蚌最佳吊养密度和深度分别为18只/m^3和40 cm。     

饵料中添加艾叶对鲤鱼增重的影响

设4个0.5米~3水族箱,每箱放养个体大小基本相同的夏花鲤鱼30尾,每箱为一处理组,1～4组的基础饵料中分别添加0.2%、0.5%、1%和2%的艾叶粉,喂养42天。结果,1组的增重效果低于其它组(P<0.01);2、3、4组的增重效果比较无统计学差异。用含0.5%艾叶粉的颗粒饵料分别于两个渔场的池塘内饲养1龄鲤鱼,结果,各试验组的生长率比相应的对照组分别提高17.39%和45.77%;各试验组的增长率比相应对照组分别提高15.39%和53.85%。     

A mistaken method for correcting potential bias in genetic testing of common carp, Cyprinus carpio L., and tilapias, Oreochromis spp.

Abstract. The aim of this investigation was to evaluate the phenotypic coefficient of regression of weight gain on initial weight as a correction factor in genetic testing programmes. A correction factor is required in order to remove the biasing effect of variation in initial weight among genetic groups tested, on their weight gain. In a genetic testing programme, involving common carp, Cyprinus carpio L., the environmentally generated coefficient of regression of weight gain on initial weight was used as a correction factor. It was estimated with the aid of the'multiple nursing technique'. In other genetic testing programmes, not accompanied by multiple nursing, the phenotypic regression coefficient of weight gain on initial weight was used as a correction factor. These factors were compared by computing a series of each coefficientfrom a data set, consisting of the results of 10 yearly experiments and including 21 different experimental treatments. The results of this analysis showed that the phenotypic regression coefficient generated unreliable and often inflated estimates of the correction factor, relative to the estimate generated from multiple nursing, which we regard as reliable. Adequate genetic testing programmes therefore need to be accompanied by multiple nursing, unless test progenies are stocked at identical weights.     

Genetic differences in susceptibility to two diseases among strains of the common carp

In a test involving 5 inbred strains, and 9 strain crossbreds of the common carp, one inbred strain was found to be infected by Epidermal epithelioma disease and a second inbred strain was infected by a swim bladder inflammation. Crossbreds between these 2 strains, as well as between them and other strains did not show a single fish infected by either disease. It was concluded that susceptibility to both of these diseases is controlled by recessive genetic factors. It appears that the decreased incidence of Epidermal epithelioma in Israeli fish ponds in recent years has been due to the increased use of selected crossbred carp fry. The incidence of Epidermal epithelioma was twice as high in experimental ponds with a high stocking rate than in those with a lower stocking rate.The swim bladder inflammation was apparently due to a blockage of the pneumatic duct, with secondary infection by Aeromonas liquefaciens.     

Impact of varied frequency of nitrogen fertilization on the grow‐out performance of Labeo rohita (Hamilton)

A grow‐out monoculture experiment for rohu, Labeo rohita was conducted for 1 year in nine earthen ponds of 0.04 ha each to study the impact of varied frequency of nitrogen fertilization on fish growth. Ponds were stocked at 8000 fingerlings ha^?1 density. While ponds were applied with cattle manure and phosphate fertilizer at conventional dosages followed for grow‐out carp culture, nitrogen fertilization was carried out at 15‐, 10‐ and 7‐day intervals and were designated as treatments T‐1, T‐2 and T‐3 respectively. Although all the water parameters in the treatments were within the suitable range for grow‐out carp farming, annual average concentration of dissolved oxygen (DO), plankton as well as availability of nutrients such as total ammonia‐ and nitrate‐nitrogen in ponds were significantly higher in T‐3 compared with T‐1 and T‐2. Greater fluctuation of critical parameters like DO, plankton concentration and total ammonia nitrogen were observed in T‐1 and T‐3 while the same were more consistent in T‐2, revealing the prevalence of a better growing environment in the latter. Fish in T‐2 also showed better specific growth rate, higher body weight attainment and higher biomass yield compared with the other two treatments, revealing the desirability of nitrogen fertilization at 10‐day intervals in carp culture.     

长江鲢、草鱼原种——人繁群体生长差异与生化遗传变化↑（*）

用完全随机区组设计的方法在三个池塘中进行了源于长江的鲢，草鱼原种与封闭人繁群体子三代１龄鱼种阶段的生长比较试验。结果表明；原种鲢，草鱼的体长绝对增长高出封闭人繁子三代群体１７－２１％，相对增长快１３－１８％；体重绝对增重高出２５－２６％，相对增重快１５－２０％。但这些差异均未达数理统计上差异显著的标准。     

A genetic study of the growth performance of silver carp from the Changjiang and Zhujiang Rivers

From 1982 to 1984, experiments were conducted, using a randomized block design, on the growth rate of wild and hatchery populations of silver carp from the Changjiang and Zhujiang Rivers in typical integrated fish culture ponds at Shanghai and Guangdong. Repeated experiments in both southern and eastern China produced identical results: there were significant differences in the length and weight gain of these populations. Both wild and hatchery populations of silver carp of the Changjiang River gained about 10% more body weight than those of the Zhujiang River. Wild silver carp gained 3–5% more than hatchery stocks from both sources. Therefore, wild silver carp from the Changjiang River grew about 15% more rapidly than hatchery silver carp from the Zhujiang River. Data analysis showed that the significant differences in weight gain among these four populations of silver carp could be attributed to a strong genetic component.     

Seasonal Differences in Growth Performance of Four Strains of Common Carp,Cyprinus carpio in India

To assess strain related differences in growth performance and growth patterns under the same culture environment, four strains of common carp, two each of the scale carp, Cyprinus carpio var. communis (Chinese big-belly carp and long bodied carp) and mirror carp, C. carpio var. specularis (scattered carp and linear carp) were communally stocked in three fertilized earthen ponds of 0.14 ha each at 5,000 fish ha^?1 in the ratio of 1:1:1:1 during an 11-month (February to December) culture cycle. Chinese big-belly carp grew larger than other groups, among which there were no significant differences. Scale carp strains performed relatively better than mirror carp at higher temperatures and then essentially stopped growing as temperatures declined into winter. The strains of mirror carp, on the other hand continued growing well later into the cold season.     

Effect of supplemental feed type on water quality,plankton and benthos availability and carp (Cyprinus carpio L.) growth in semi‐intensive monoculture ponds

A four‐and‐a‐half months study was conducted in nine earthen ponds to evaluate the addition of different supplemental feeds as a management tool for enhancing natural food availability and common carp growth, while maintaining optimal water quality in the semi‐intensive system. Three supplemental feeds were used: commercial extruded and pelleted feed with 25% protein and 7% fat and cereals. The type of supplemental feed did not influence water quality, except hardness, but significantly affected abundance of cyanobacteria, natural food availability and common carp growth. The use of pelleted feed was related to the lowest abundance of cyanobacteria in the ponds. For the two groups of large zooplankton, Cladocera and Copepoda, abundances were higher in the ponds with pelleted feed compared with the ponds where cereals and extruded feed were used. The abundance of benthic macroinvertebrates in the treatment with pelleted feed was three times higher than in the other two treatments. The results of this study indicate that pelleted feed can help farmers not only as a source of nutrients for carp growth but also indirectly as a management tool for maintaining ecological stability and control of cyanobacterial bloom in ponds.     

微生态制剂对鲤、鲫和草鱼养殖池塘效益的影响

以枯草芽孢杆菌为主的主要用于促进鱼类消化生长的微生态制剂I、多种混合微生物主要用于调节水质的微生态制剂II,或是两者混合使用的方法,比较研究了黑龙江省及辽宁省池塘养殖的鲤（Cyprinus carpio）、鲫（Carassius auratus）和草鱼（Ctenophyargodon idellus）的增重率、饲料系数及药价等效益。结果表明,单种或者混合使用微生态制剂均对池塘养殖鲤及草鱼的增重率、饵料系数及用药价格有一定影响,同时使用两种微生态制剂提高鱼类增重率最显著,辽宁省和黑龙江省分别提高了423.57%和90%;而两省养殖池塘的药价也分别降低了29%和56.25%。微生态制剂I及混合同时使用两种微生态制剂均能显著降低饲料系数,辽宁及黑龙江分别降低0.35及0.05。结果可见,适当使用微生态制剂对辽宁草鱼及黑龙江池塘养鲤效益有较好影响,对减少用药、发展绿色养殖业具极大的推动作用。